Boat propulsion device



1968 T. E. GRAVENSTRETER 3,410,243

BOAT PROPULSION DEVICE Filed Jan. 3, 1967 INVENTOR. mom/Is E. Gmvsusrmsrm.

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' km/wwuz 610a f'z mw flame s United States Patent 3,410,243 BOAT PROPULSION DEVICE Thomas E. Gravenstreter, 4419 Washington Blvd., Indianapolis, Ind. 46205 Filed Jan. 3, 1967, Ser. No. 606,682 2 Claims. (Cl. 11511) ABSTRACT OF THE DISCLOSURE A propulsion method and device for a watercraft which operates by the low pressure discharge of air from the watercraft at a point below the surface of the water supporting the Watercraft. The watercraft has a plate arrangement which is swingably mounted on the watercraft above the air discharge and which provides an adjustably inclined surface against which the air acts to propel the watercraft. An alternative embodiment has its air discharged into a water filled conduit which extends from the bottom to the rear of the boat.

BACKGROUND OF THE INVENTION Field of the invention-This invention relates to method and apparatus for the propulsion of watercraft.

Description of the prior art.The present commercially accepted practice of watercraft propulsion is to pump the water through a positive displacement centrifugal or axial flow pump. Such a pump frequently has an acceleration chamber downstream of the pump impellers where water is contained under pressure prior to its flowing out of the pump in the form of a jet. Other types of watercraft propulsion have been conceived which involve the pumping of a stream or a jet of air from the rear of the watercraft. However, these arrangements also rely upon the placing of the fluid under pressure and the expelling of the fluid from the rear of the craft with a substantial amount of kinetic energy. There is much room for improvement in the efliciency of propulsion provided by such prior art arrangements.

SUMMARY OF THE INVENTION One embodiment of the apparatus of the present invention might involve a propulsion apparatus for a watercraft comprising a container mounted on the watercraft, means for providing gaseous fluid to the container, said container having a passage means leading from the in side of the container to the exterior of the watercraft at a location below the surface of the supporting water, said watercraft having an inclined surface extending upwardly from said passage means and inclined away from the desired direction of movement.

One embodiment of the method of the present invention might involve the propelling of a watercraft by submerging a container in the water supporting the watercraft, providing passage means in the container at a point below the surface of the water supporting the watercraft, moving a gaseous fluid into the container to a sufliciently high pressure to cause the water level in the container to move to a point below the upper edge of the passage but above the lower edge of the passage means and causing the gaseous fluid to move from said passage means up an inclined surface of the craft which slopes in a direction away from the desired direction of movement of the craft.

A primary object of this invention is to provide an improved propulsion arrangement for a watercraft.

Another object of this invention is to provide a boat propulsion device which makes use of a source of energy presently neglected and wasted in boat propulsion systems.

Related objects and advantages will become apparent as the description proceeds.

The full nature of the invention will be understood from the accompanying drawings and the following de scription and claims.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more particularly to the drawings, there is illustrated a watercraft 10 which has a hull 11 of relatively deep draught, that is which extends a substantial distance downwardly into the water 12 supporting the watercraft. Fixedly mounted upon the rear of the hull 11 is a container 15. At least a portion of this container 15 is submerged in the water 12 supporting the watercraft. A pump 16 is driven by an engine 17 so as to pump air into the container 15. The submerged container 15 has a plurality of passages or openings 20 which lead from the inside of the container to the exterior of the watercraft at a location below the surface of the supporting water 12.

Swingably mounted upon the watercraft is a plate assembly 21 which includes two plates 22 and 23. Th plate arrangement 21 is connected to the watercraft by means of a hinge 25 which extends across the entire plate arrangement 21 from side to side of the watercraft and which incorporates means sealing off the area 26 from the area 27. This sealing off is accomplished in order to prevent air exiting through the passage means 20 from moving upwardly through the hinge 25 into the area 26. Instead this air should move upwardly across the rearward inclined face of the plate 22.

Secured to the upper distal end of the plate 22 by a further hinge arrangement 30 is the plate 23. The plate 23 has an upwardly projecting member 31 which is swingably connected to a rod 32 extending through a ball 35. The rod 32 is slidable in the ball 35 so as to permit projecting of the rod to the dotted line position illustrated in FIG. 2. When the rod is so projected, the plate 23 is maintained in a horizontal position as illustrated. Thus, no matter what the projected position of the rod 32, the plate 23 remains in a horizontal position while the inclination of the plate 22 is changed.

Fixed to the plate 22 are a plurality of rearwardly extending vertical plates 36. These plates act as guides for the air moving out of the passages 20. Further vertical plates 40 are fixed in alignment with the sides of the watercraft and are suitably positioned so that, no matter what the location or positioning of the plate arrangement 21, the plates 40 are in engagement with the opposite ends of the plates 22 and 23 making up the plate arrangement 21. It can be appreciated that the plates 40 also act similarly to the vertical plates 36 to guide the air as it moves out of the passage means 20.

In operation, the pump 16 of the propulsion device is driven by the engine 17 causing air to be pumped into the submerged container 15. This air moves out of the passage means 20, thence upwardly across the inclined plate 22 so as to propel the watercraft leftwardly as viewed in FIG 2. Of course, the reason why the air moves upwardly is the fact that it is lighter than the water surrounding it. The upward movement of the air, however, also moves Water ahead of it displacing the water rightwardly as viewed in FIG. 2, causing the boat to be moved leftwardly by reason of the action producing a reaction. The air and the water which it moves or pushes ahead of it is not entirely released until the air has moved out of the plate arrangement 21, that is, until the air has moved rightwardly past the upper horizontal plate 23.

The reason for providing the adjustable inclination of the plate 22 to the dotted line position and between the solid line and the dotted line position and beyond the dotted line position is to accommodate the device to increased speeds. When the watercraft moves at a higher speed, the inclination of the plate 22 should be greater or more like the dotted line position as compared to the solid line position in order to obtain the highest efficiency for that speed.

It should be understood that the air which moves out of the passage means 20 is only under a sufiicient amount of pressure to overcome the head created by the position of the passage means below the surface of the supporting water 12.

For this reason, the openings 20 are made sufficiently large so that the maximum output of the pump 16 cannot create enough pressure in the container to move the water level 50 within the container 15 below the lower edge 51 of the respective openings 20. Stated more correctly, assuming that the openings are not in the straight line suggested by the dotted line 52 of FIG. 1 and further assuming that some of these openings are below others of these openings, the pump 16 is not sufficiently strong enough to cause the water level 50 to move below the lower edge 51 of the lowermost passage or passages 20. In this way, the watercraft can assure that the pressure within the container 15 does not rise above that pressure necessary only to overcome the head produced by the distance of the openings 20 below the upper surface of the supporting water 12. If the air within the container 15 did have an extremely high pressure, the air would be squirted outwith a great amount of kinetic energy through the openings 20, moving directly rearwardly and not producing the action-reaction effect against the inclined surface 22.

Referring now to FIG. 4, there is illustrated an alternative embodiment of the present invention which operates in the same fashion as the embodiment described above with the following exceptions. The inclined surface produced by the inclined plate 22 is replaced by the surface 60 of a conduit 62 which extends through the watercraft 65 from the bottom 66 of the watercraft to the rear 67 thereof. The passages or passage means 20 are replaced by openings or passages 70 which extend all the way around the conduit 62 but still at a location well below the upper surface 71 of the water 72 supporting the Watercraft 65. The submerged container 15 is represented by the container 72 which surrounds the conduit 62 and which is in communication with the passage means or openings 70. An engine and pump similar to the engine and pump 16 and 17 is provided in the watercraft 65 and the output of the pump is channeled into the container 72 through the conduit 75. The operation of the embodiment of FIG. 4 is generally identical to the operation of the embodiment of FIG. 2 with the exception that the inclined sur- 6O face is not adjustable as to inclination as is the inclined 4 surface provided by the inclined plate 22 of FIGS. 1 and 2.

It will be evident from the above description that the present invention provides an improved propulsion arrangement for a Watercraft. It will be further evident that the present invention provides a boat propulsion device which makes use of a source of energy presently neglected and wasted in prior art boat propulsion systems.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention and the scope of the claims are also desired to be protected.

The invention claimed is:

1. In a watercraft, propulsion apparatus for the water craft comprising a container mounted on the watercraft, means for providing gaseous fluid to the container, said container having a passage means leading from the inside of the container to the exterior of the Watercraft at a location below the surface of the supporting water, said watercraft having an inclined surface extending upwardly from said passage means and inclined away from the desired direction of movement, a first plate hinged at its lower end to said watercraft above said passage means and providing said inclined surface, a second plate hinged at a proximal end to the distal upper end of said first plate, a control rod pivotally secured to said second plate and extending into said watercraft, said control rod being projectable from said watercraft to decrease the slope of said first plate and retractable into said watercraft to increase the slope of said first plate.

2. In a watercraft, populsion apparatus for the watercraft comprising a container mounted on the Watercraft, means for providing gaseous fluid to the container, said container having a passage means leading from the inside of the container to the exterior of the Watercraft at a location below the surface of the supporting water, said watercraft having an inclined surface extending upwardly from said passage means and inclined away from the desired direction of movement, a first plate hinged at its lower end to said watercraft above said passage means and providing said inclined surface, a second plate hinged at a proximal end to the distal upper end of said first plate, and means for decreasing and increasing the slope of said first plate while maintaining said second plate generally horizontal.

References Cited UNITED STATES PATENTS 626,140 5/1899 Carr -11 1,861,035 5/1932 Tarn 1l5l1 FOREIGN PATENTS 734,507 8/1955 Great Britain.

MILTON BUCHLER, Primary Examiner.

TRYGVE M. BLIX, Assistant Examiner. 

